Histotripsy Group
    Biomedical Engineering Department, University of Michigan




High Speed Imaging

Acoustic Monitoring

Optical Monitoring



Histotripsy Mechanism -> High Speeding Imaging

High Speeding Imaging


Each histotropsy pulse generates a dynamically changing cluster of microbubbles. The bubbles behave as one dynamic unit, growing and shrinking together, and therefore this bubble cluster can be called a "bubble cloud" as defined by previous cavitation researchers.

Important time scale:
Histotripsy Pulse: several μsec
Collapse cycle of the bubble cloud: several hundred μsec
Residual bubbles from cloud collapse: several msec



Non-prenucleated single pulse in water



Prenucleated 3 cycle (4 μs long at 750kHz) pulse in water



Prenucleated 15 cycle (20 μs long at 750kHz) pulse in water



10 cycle (14 μs long at 750kHz) pulse at a tissue-water interface



10 cycle (14 μs long at 750kHz) pulse in tissue-mimicking gel phantom (taken with long distance microscope)




References:
Xu Z, Raghavan M, Hall TL, Chang C-W, Mycek M-A, Fowlkes JB, Cain CA, "High Speed Imaging of Bubble Cloud in Pulsed Cavitational Ultrasound Therapy - Histotripsy," Proc. IEEE International Ultrasonics Symposium, 1D-4 (2006).